| 摘要 |
PURPOSE:To decrease the entire code length while keeping the correction capability by regarding a check part of an original code as a part of information to form a overlapped code and applying addition of modulo to the code. CONSTITUTION:The information inputted from an information input terminal 4 is coded by a Cr coder 6 at each K-bit and converted into an n-bit code word. The operation above is repeated by N times, a UR coder 7 generates a check symbol of (N-k) on a GF(2<n-k>) from a check part of the code word Co while regarding it as K symbol information to form an N-symbol code word, an adder A1 applies addition of modulo 2, and each symbol of the check part of the code word Co and the code UR is subject to addition of modulo 2 corresponding to a bit. Then a synthesized code word Cz is obtained. An internal recovery check vector is formed by an information part of the reception vector and addition of modulo 2 is applied to the check part of the reception vector. When an error is within the correction capability range of the code UR, it is corrected entirely and the code word UR transmitted from the transmission side is recovered by a UR recovery device 10. In applying reception vector modulo 2 addition to the code word UR decoded correctly by a UR decoder 11, a received word of the code word Co is obtained.
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